Under contract with the University Medical Centre, Utrecht, TNO Human Factors has conducted research to investigate the effect of diabetes on driving behaviour. In a driving simulator experiment, patients with diabetes and non-diabetics were confronted with various traffic situations. The subject groups always drove the conditions twice. In this, the patient groups drove the route once with euglycaemia (a normal blood sugar level) and once with hypoglycaemia (low blood sugar level). The non-patient group drove the route twice with a normal blood sugar level. Subjects did not know in what condition their blood sugar level would be decreased to the level of hypoglycaemia. In the analysis of the diabetic group, difference was made between people who were aware of their blood sugar level being low and those who did not notice the status of hypoglycaemia. Ninety subjects participated in a driving simulator experiment. Subjects drove on the motorway, a rural road and a city road. During normal driving situations, some critical incidents were encountered (e.g. braking lead vehicle, deciding who has the right of way, coping with curves). During driving, behavioural variables were measured. These variables were Time-to-Line-Crossing, Time-To-Collision, crossing road markings, response times to critical situations and responses to a secondary task. By comparing driving performance between non-patients and patients, and between a normal blood sugar level and hypoglycaemia, the effects of diabetes on driving performance and traffic safety were established. The results showed that in case of a low blood sugar level in Type II diabetics (non-insulin dependent), there is a clear decrease in performance, although some of the effects are also present in that type of diabetics with normal blood sugar levels. Type I (insulin dependent diabetics) diabetics did not show any decreased driving performance, not even with low blood sugar levels. (A) For the covering abstract of the conference see ITRD no 207828. The reprints are also available at the web - http://www.vti.se/pdf/reports/K18APart1.pdf; http://www.vti.se/pdf/reports/K18APart2.pdf and http://www.vti.se/pdf/reports/K18APart3.pdf.
Abstract